Over-heating problem...Just want some answers!

[drake3988]

I have a 97 sr5 and the last month he has been acting up. The temp gauge rises to red when sitting still and takes awhile to level back out once I am back to driving. I took it to a mechanic today and he sad he is unsure and said he would start with the radiator cap and the thermostat. I had my radiator flushed and it didn't really help. I have been thinking it was my radiator and needs to be replaced, but i am just worried about it being a head gasket. It doesn't seem to want to hold coolant but that's the only symptom that could be associated with that. I am taking it to Toyota to run a diagnostic and compression test Thursday. What do you guys think? any opinions are welcome, just trying to hear about prior experience with this. Thanks again

 

[PitbullRescuer]

Is it loosing coolant? Can you smell it or see any coolant burning out of the exhaust?

If it's just getting hot, most likely has a blockage somewhere. Flush the sh*t out of it, pull the lines off the heater core and flush it, pull the rear heater lines and flush the rear core also. Replace the thermostat and go from there.

 

[BrianSD_42]

Has it thrown a CEL / code?

Have it read and tell us the exact code(s)

 

[Gerdo]

Are you saying that you are loosing coolant?

Obviously the thermostat and the radiator cap are simple things to try.
I'm thinking, water pump or fan clutch. The water pump can leak, it can also not move coolant if the veins rust thru. If the fan clutch is bad, the fan will not engage enough to pull enough air thru the radiator. It may be spinning but not pulling enough air.

I'm thinking more toward the fan clutch.

Will it overheat just idling in your driveway?
As a test.
If you have a strong electric fan (a leaf blower may work)(or a water hose).
Run the vehicle, idle, and blow air thru the radiator, or hose the radiator with water. If it doesn't overheat, I would bet on the fan clutch.

 

[drake3988]

It is losing coolant but not sure where. No smell of it either.

I did get a check engine code but it was for a cylinder 4 misfire, but that was because of a spark plug issue and is now fixed.

I will try the idle test and maybe also i may need to flush it myself. I will keep all those things in mind and check some this week. Thanks for the replies and i hope to have more Info tomorrow and will post once i find out anything different.

 

[Gerdo]

There is a freeze out plug at the top/back of the engine by the back of the intake manifold that is known to possibly leak. Mine is weeping a little. It runs down the back of the engine and over the transmission. Most of the coolant evaporates before it drips.

This is probably unrelated to the overheating.

Also look above where the lower radiator hose meets the engine (this is the thermostat housing). If you see dried coolant (pinkish/reddish/whiteish crusties) above this housing, the water pump may be weeping. This is usually where it shows up. The water pump is behind covers and driven by the timing belt.

 

[drake3988]

well I took it to Toyota and had them do a diagnostic test. My 4runner has a clogged and cracked radiator. They also recommend the thermostat being replaced with the radiator.

I was a little concerned with what else they told me. The mechanic said that my engine sounds like a diesel engine. He said he can hear something from the left head but said he needed to fix the radiator and also take more time to figure it out. Not sure if it was kinda BS or what but I hope its not really serious. What do you guys think?

 

[TheDurk]

Well, if you are going into the red, you could be losing coolant out the overflow when the fluid boils. Have you ruled out the fan clutch? This is a common problem now on our generation; I replaced mine two summers ago.

I say this only because my confidence level on dealer diagnostics is pretty low.

 

[stevec5000]

It's easy to tell if the radiator is good. They have testers for it but all you have to do is touch the inlet at the top and it will be Really HOT but touch the outlet at the bottom and it should be cold as long as the fan is running. Actually you don't need to touch the inlet at the top but if the outlet at the bottom isn't cold the radiator isn't working and is probably corroded and clogged up.

 

[nissanh]

Replace the radiator. I had 97 4runner and on one summer I saw temp going up! Replace the fan clutch. No luck. Then removed the thermostat..... and all the water in the radiator now escaped! I then saw the radiator core is blocked with dirt! Replace the radiator and see. You can buy a radiator For $80 ebay with free shipping.